Fig 2. The patient movement network in England.

A) Strong connections (darker lines) between hospitals (circles) are regionally bound, and form a strong community structure (circle colours). B) The distribution of connection weights shows that most connections between hospitals are weak (i.e. few shared patient between hospitals). C) The degree of a hospital (the number of hospitals it is connected to by shared patients) is related to the total number of patients it exchanges with other hospitals (hospital strength).